1. Field of the invention
2,4-diaminopyrimidines, particularly 6-piperidino-2,4-diaminopyrimidine-3-oxide which is known by the name "Minoxidil", are well known in the art. This product is used in human therapeutics particularly for its antihypertensive properties and for topical application in the treatment of baldness and alopecia.
2. Description of the prior art
A disadvantage of "Minoxidil" is that it is practically insoluble in water which limits its use in that formulations having relatively low proportions of water and containing high concentrations of alcohol or polyol are in general not well tolerated.
However, certain salts of "Minoxidil" are known, in particular the sulfate, the 4-N-acylthiazolidine carboxylate and the L-5-oxoproline salt.